Drill



Oct. 25, 1932. L. M. PEARCE ET AL DRILL I Filed April 14, 195]:

Patented Oct. 25, 1932 LOUIS M.'PEARCE AND WALTER L. CHURCH, OF HOUSTON,TEX-AS DRILL Application filed April 14,

This invention relates to a drill.

, One objectofthe invention is to provide a drill having a head and a.detachable blade, or other cutter, detachably secured to the head in anovel manner.

Another object of the invention is to pro vide novel means for securingthe blade, or cutting member, in the head whereby the play of saidcutting member in the head, due to wear or otherwise, may be taken up sothat said cutting member may be secured immovably in the head.

lVith the above and other objects in view this invention has particularrelation to cerrain novel features of construction, arrangement of partsand use, an example of which is given in this specification andillustrated in the accompanying drawing, wherein F igure'l shows a sideview of the drlll.

Figure 2 shows a transverse sectional view taken on the line 22 ofFigure 1.

Figure 9 shows a fragmentary sectional 0 view taken on the line 3-3 ofFigure 1.

Figure 4 shows a fragmentary sectional view taken on the line 4-4 ofFigure 1. t Figure 5 shows a fragmentary vertical sectional view of amodified form of the drill, and

Figure 6 shows a fragmentary vertical sectional view of anothermodification thereof. Referring now more particularly to the drawing,wherein like numerals of reference designate similar parts in each ofthe figures the numeral 1 designates the head whose upper end may bethreaded for attachment of a drill collar, or drill stem, thereto. Thehead may be of any desired contour and length and has a transversemortise 2' across its lower end separating said end into the prongs 3,3.0 A suitable cutting, or abrading, member 4 is provided whose lower endmay have any selected type of boring members, the cutting blades 5, 5being shown, which have cutting edges forwardly curved in oppositedirections.

The upper end of the member 4 is fitted into the mortise 2. In the formshown'in Figures 1 to 4 inclusive there are the externally threaded,internally tapped, bushings V 6, 6, which are threaded through therespecings are each formed of two parts, the inner 1931., Serial No.529,930.

tive prongs 3, 3 on opposite sides of the head. The inner ends of thesebushings bear against the cutting member 4 above. the respective blades5, 5 and said member 4may have shallow recesses 7, 7, if desired toreceive the inner ends of the bushings. There are the bolts 8, 8 to holdthe prongs against spreading and also to hold the cutting member4 andthe bushings 7 place. The free end of each bolt isprovided with externalthreads 0, which are preferably pitched a direction the opposite of thatof the external threads of the corresponding bushing and each bolt ispassed through one prong andythreaded through the opposite bushing. Theheads of 5 the bolts vand bushings arecountersunk into the correspondingprongs and the heads of the bushings are castell'ated to receive thecotter keys 9 which pass also through the corresponding ends of thebolts.

The bolts 8 will prevent the prongs from spreading and in case themember 4 becomes loose in its mortise from wear or other cause thebushings 6 may be tightened up to force the member 4 firmly against theinside face of the opposite prong so as totake up the play and to holdthe blades against any movement relative to the head.

'In the form shown in Figure 5 the bushends 6 thereofseatingragainst themember 4 in thesame manner as shown in Figures 1 to 4 and the outerends, or heads, 6 thereof seating in the sockets of the correspond ingprongs; The bolts 8,,0fthis form are threaded through these sectionalbushings, and secured, as hereinabove described, and bushings of thistype are not necessarily screwed to the prongs 3.

In the form shown in Figure 6 the'bolts 8 are fitted through the prongs3v and are threaded through the cutting member 4 and their free ends arereduced, forming the external shoulders, as 10, which abut the op- Iposing annular shoulder. 11 in the corresponding prong 3 and beyond theshoulder 10, each bolt 8 is externally threaded to receive the nut 12which is counter-sunk in its prong. The bolts8, 8 of Figures 5 and 6 aresecured in place by cotter keys 9 as in Figures 1 to 4.

In case the cutting member l, of Figure 5, becomes loose from wear, orother cause, the bolts 8 i ay be tightened up to draw said memberclosely against the adjacent prong 3 to take up the play. i

y The head has an axial water course 13 and the boring member has thesaid channels 14, 1% through which a flushing fluid may be do liveredfrom the course 13 onto the forward sides of the blades.

In the forms shown in Figures 1 and 5 should the bolt 8 become brokenthe bushing 6, or 6, as the case may be, will hold the cutting member lagainst dropping into the bore and interfering with further drillingoperations. In the form shown in Figure 6. the bolt 8' is made large sothat it is not liable to break and has a threaded connection with thecutting member l so that should the reduced end of said bolt 8" becomebroken oh the cutting member i will still be held in the head againstdropping in the bore.

The drawing and description disclose what is now considered to bepreferred forms of the invention by wayof illustration only while thebroad principle of the invention will be defined by the appended claims.

What We claim is:

l. A drill comprising a head having prongs spaced apart forming amortise between them, a boring member in said mortise, a bushing througheach of the prongs on opposite sides of the axis of the head whose innerends abut said member and bolts through said prongs and boring memberfrom opposite sides of the drill and having threaded connections withsaid bushings.

2. A drill comprising a head having spaced prongs forming a mortisebetween them, a boring member inserted into said mortise, a bushingthrough each prong and operative against opposite sides of the boringmember, said bushings being arranged on opposite sides of the head, andbolts through the head and boring member, said bolts having threadedconnections with said bushings.

3. A drill comprising a head having a transverse mortise, a boringmember inserted into said mortise, bolts through the head and boringmember from opposite sides, bushings threaded onto said bolts and beingoper ative against opposite sides of said boring member. 7

4. A drill comprising a head having a transverse mortise, a boringmember inserted into said mortise, bolts through the head and boringmember, bushings threaded onto said bolts and being operative againstopposite sides of said boring member, said bu'shin being formed ofsections.

5. A drill comprising a head having a transverse mortise, a boringmember inserted into said mortise, bolts through the head and boringmember, bushings threaded onto said bolts and being operative againstopposite sides of said boring member, said bushings also having threadedconnections with the head.

6. A drill comprising a head, a boring member at the lower end thereof,said head and boring member being'provided one with spaced prongs andthe other being shaped with a tenon fitted between said prongs, abushing through each or the prongs 011 opposite sides of the axis of thehead whose inner ends abut said tenon and bolts through said prongs andtenons from opposite sides of the drill and having threaded connectionswith said bushings.

In testimony whereof we have signed our names to this specification.

LOUIS M. PEARCE. WALTER L. CHURCH.

